How to Repair a Husqvarna 359 Chainsaw Piston
- 1). Remove the cylinder cover and the air filter. Wipe around the air filter's mount and the cylinder's base to keep anything from entering the crankcase during disassembly.
- 2). Remove the two screws holding the choke cover plate over the carburetor. Remove the plate covering the carburetor and intake manifold. Unscrew the carburetor from its mounting plate.
- 3). Remove it and the attached throttle linkage from the engine. Unscrew the intake manifold and remove from the engine. Remove the spark plug's rubber plug from the spark plug.
- 4). Unscrew the spark plug and remove. Unscrew the four muffler screws, and remove the muffler from the exhaust port. Unscrew the four screws holding the cylinder to the crankcase. Lift the cylinder straight off the piston and crankcase.
- 5). Place the clean cloth over the crankcase opening and wrap it around the connecting rod, to prevent any dust or dirt from getting in the crankcase. Remove the retaining clips on the piston and pull the pin out. Take the piston off the connecting rod and wipe it down with the rag.
- 6). Inspect the cooling fins, exhaust port and threads on the cylinder for any damage or worn seals. Check the cylinder walls for any scratches, nicks or dents. If there is heavy damage and a number of dents or nicks, you will likely need to replace the cylinder and possibly the exhaust port.
- 7). Check the piston for any seizure marks and that the piston ring is not stuck in its groove. Buff out any light scratches and small dents with the emery cloth. If there are too many dents or they are too deep, replace the piston and cylinder.
- 8). Reinstall the piston by putting the pin back through the holes. Reattach the new piston clips. Lubricate the piston and piston ring with engine oil lubrication. Make sure the piston ring is in line with its retaining pins to prevent ring rotation.
- 9). Reset the cylinder with the piston/cylinder mounting tool set from Husqvarna. Compress the piston ring to the appropriate pressure. Set the cylinder back over the piston and piston ring. Tighten the four retaining screws with the screwdriver.
- 10
Reassemble the rest of the parts.